You'll like the BL upgrade. BL motors are really cool.

The belt drive is pretty cool. It gives much better tail authority. In fact collective driven tails are the ultimate for tail control. If that's what you want then a driven tail is the only way to go.

You will have to change everything out though. The 3-in-1 wouldn't work in that app. The only thing you could use is the Rx. The motor would have to be upgraded because it would need to be more powerful to drive the tail. You know how hot it gets now. How hot do you think it would get from all the extra drag and load of a belt system and tail rotor? You'd also need a gyro and tail servo.

If I wanted a driven tail heli I think I'd go for the barebones HB King V2 from Helidirect for $88. It was designed for with a belt drive and it has a one way bearing for autos (I think). I don't think that mod from Freestyle allows for a one-way bearing. If I was going with a set-up like that I'd want the heli to be able to do anything I could think of including autorotations.

That said I really do like the tail motor set-up for it's simplicity and it's sleekness. I like the fact that it doesn't have linkage hanging out and I think it's easier to repair. Plus I like to go the road less travelled. I guess it's a character flaw.

My goal is to get a tailmotor heli to perform like a driven tail heli just because it's hard to do.